Method for neutralization, adsorption, and absorption of hazardous or otherwise undesired compounds in a tobacco product

ABSTRACT

A tobacco product comprising nanocrystalline particles and methods of reducing the levels of undesirable compounds in tobacco smoke are provided. The nanocrystalline particles are effective sorbents of numerous toxic compounds released by burning tobacco and may be incorporated into the tobacco itself, incorporated into a filter element, or incorporated into the fibers of a wrapping paper.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 61/044,758, filed Apr. 14, 2009, which is incorporated by reference in its entirely.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is generally directed toward abatement of hazardous, or otherwise undesired compounds contained in tobacco smoke through neutralization, adsorption, and absorption by the incorporation of nanocrystalline particles into tobacco products.

2. Description of the Prior Art

The hazards of tobacco smoke to both the smoker and to others in the vicinity of tobacco smoke (i.e., secondhand smoke) are well documented. According to the National Toxicology Program, tobacco smoke, especially that produced by cigarettes and cigars, contains at least 250 poisonous gases, chemicals, and metals including hydrogen cyanide, carbon monoxide, butane, ammonia, toluene, arsenic, lead, chromium, cadmium, and polonium-210 (highly radioactive carcinogen), nitrogen oxides, formaldehyde, acrolien, benzene, certain N-nitrosamines, nicotine, phenol, polyaromatic hydrocarbons (PAHs). Eleven of the compounds are classified as Group 1 carcinogens, the most dangerous.

Tobacco products, especially cigarettes, can employ cellulose filters devices to assist with removal of smoke, tar and other particulate matter prior to being inhaled by the user. However, these filters do not address or mitigate the inhalation of or release into the surrounding environment of a good number of these toxic gases and chemicals. Further, traditionally unfiltered tobacco products such as cigars contain no or relatively little means to mitigate the release and inhalation of these toxic materials.

SUMMARY OF THE INVENTION

In one embodiment according to the present invention there is provided a tobacco product comprising nanocrystalline particles and tobacco. Particularly, the tobacco product may be a cigarette or cigar wherein the nanocrystalline particles are contained within the product's paper wrapping, incorporated into, mixed, and/or directly intermingled with the tobacco, or included within a fibrous filter that forms a part of the tobacco product. In certain embodiments, the tobacco product comprises between about 0.001% to about 2% by weight of the nanocrystalline particles based upon the weight of the entire tobacco product.

Exemplary nanocrystalline particles for use with certain embodiments according to the present invention include those selected from the group consisting of the oxides, hydroxides, halides, carbonates, nitrates, sulfates, and phosphates of metals, metalloids, and combinations thereof. In one embodiment, the exemplary nanocrystalline particles have an average crystallite size of between about 2 to about 25 nm. In another embodiment, the nanocrystalline particles may be amorphous and have an average crystallite size of less than 2 nm. In still other embodiments, the nanocrystalline particles have an average surface area of at least 20 m²/g.

In another embodiment according to the present invention, there is provided a method of reducing the level of reducing the level of undesirable components in tobacco smoke from a tobacco product comprising the step of incorporating a quantity of nanocrystalline particles into the tobacco product. The tobacco product may be constructed according to any of the embodiments described herein, and likewise, the nanocrystalline particles used with the tobacco product may be any of those nanocrystalline particles described herein. At least a portion of the tobacco product is combusted and thereby generating tobacco smoke (including carbonaceous smoke particulates) and one or more undesirable compounds. The nanocrystalline particles contained within the tobacco product sorb smoke particulates and/or at least one of the one or more undesirable compounds contained in said tobacco smoke thereby preventing those materials from being taken in by the smoker or contaminating the surrounding environment.

In addition to the benefits to the smoker and those in the immediate vicinity of the smoker, embodiments according to the present invention also reduce the levels of third-hand smoke contaminants deposited on surfaces exposed to tobacco smoke.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cigarette made in accordance with one embodiment of the present invention wherein the cigarette paper is coated with or has incorporated therein a quantity of nanocrystalline particles;

FIG. 2 is a cross-sectional view of a cigarette made in accordance with another embodiment of the present invention wherein a quantity of nanocrystalline particles are incorporated into or mixed with the tobacco;

FIG. 3 is a perspective view of a cigarette made in accordance with yet another embodiment of the present invention with the filter portion of the cigarette partially sections, the filter portion having incorporated therein a quantity of nanocrystalline particles;

FIG. 4 is a chart depicting air filtration removal capacities for various sorbents and hydrogen chloride agent under dry conditions and 35% relative humidity conditions; and

FIG. 5 is a chart depicting air filtration removal capacities for various sorbents and acetaldehyde agent under dry and 50% relative humidity conditions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The main undesirable components of tobacco (especially cigarette and cigar) smoke are inorganic compounds such as hydrogen cyanide, carbon monoxide, and nitrogen oxide; aldehydes such as formaldehyde, acetaldehyde, butyraldehyde, crotonaldehyde, propionaldehyde, acrolien; ketones such as acetone and MEK; nitrogen compounds such as ammonia, acrylonitrile, pyridine, N-nitrosamines, and acrylamide; organic compounds such as polyaromatic hydrocarbons (PAHs), styrene, 1,3-butadiene, benzene, isopropene, toluene, phenol, fluorene, ethylene oxide, propylene oxide, and butane; and particulate phase materials such as arsenic, lead, chromium, cadmium, polonium-210 (highly radioactive carcinogen), benzo-[a]-pyrene, NNN(N′-nitrosonornicotine), NNK(4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone), naphthalene, 4-aminobiphenyl, 2-aminonapthalene, and quinoline. The present invention provides a tobacco product that is capable of reducing or eliminating the release of one or more undesirable compounds generated by the combustion of tobacco, and methods of reducing carrying out this reduction or elimination of undesirable compounds.

One embodiment of the present invention comprises the use of nanocrystalline particles that are capable of adsorbing one or more undesirable compounds released by burning tobacco. As used herein, a “nanocrystalline particle” means a high surface area particle having an average surface area of at least 20 m²/g and an average crystallite size of between 2 to 25 nanometers. If the nanocrystalline material is amorphous, the average crystallite size can be below 2 nm. The particle itself need not necessarily have these dimensions, but can present a much larger particle size. Rather it is the crystals that make up the particle that are nano-sized. In certain embodiments, the nanocrystalline particles exhibit an surface area of between about 100 to about 800 nm, or between about 300 to 700 nm. Nanocrystalline particles are prepared by conventional means or via an aerogel process described in U.S. Pat. No. 6,087,294 and Utampanya et al., (Chem. Mater. 3:175-181 [1991]) both incorporated herein by reference.

Exemplary nanocrystalline materials include oxides, hydroxides, halides, carbonates, and phosphates of metals, metalloids, and combinations thereof. In certain embodiments, the nanocrystalline particles comprise a member selected from the group consisting of the halides, carbonates, phosphates, oxides, or hydroxides of alkaline earth metals (e.g., MgO, CaO), alkali metals, transition metals (e.g. ZnO, TiO₂), and lanthanide metals, and metalloids (e.g., silicon oxides). The materials may be in the form of a singular component or a multi-component mixture, in the form of a powder, embedded particles in or supported on a media (i.e., paper, Filter, or other components of cigarettes) or in granular or otherwise aggregated form. Exemplary metal oxides and metal hydroxides include MgO, CeO₂, CaO, TiO₂, ZrO₂, FeO, V₂O₃, V₂O, Mn₂O₃, Fe₂O₃, NiO, Fe₃O₄, CuO, Al₂O₃, ZnO, SiO₂, Ag₂O, SrO, BaO, Mg(OH)₂, Ca(OH)₂, Al(OH)₃, Sr(OH)₂, Ba(OH)₂, Fe(OH)₃, Cu(OH)₃, Ni(OH)₂, Co(OH)₂, Zn(OH)₂, AgOH, AlOOH (alumina oxyhydroxide) and mixtures thereof, obtained from NanoScale Corporation, Manhattan, Kans., some of which under the name NanoActive®. The nanocrystalline particles may also comprise more than one metal oxide or metal hydroxide species co-solidified together (as opposed to being coated one over another). For example, the nanocrystalline particles may comprise MgO/TiO₂/Al₂O₃ or any combination of the above-noted metal oxides and metal hydroxides.

The nanocrystalline particle might be also utilized in a combination with activated carbon, as a simple physical mixture, coating of nanocrystalline particles onto activated carbon, coating of activated carbon onto nanocrystalline particles, nanocrystalline particles embedded into activated carbon, or any combination thereof.

The particles may also comprise one or more reactive species stabilized on the surface of the nanoparticle. Exemplary reactive species include halogen atoms, Group IA atoms, and ozone. The nanocrystalline particle may also be doped with a metal species such as gold, platinum, ruthenium, rhodium, or palladium to achieve a catalytic oxidation of certain contaminants. For example, CO contained in the tobacco smoke may be converted to CO₂ through such catalytic oxidation.

The particles may be coated to protect them from the moisture (i.e., air stable nanoparticles as disclosed in U.S. Pat. No. 6,860,924 incorporated by reference herein in its entirety), coated with halogens, metal halides, or with another metal oxide/hydroxide (see, U.S. Pat. Nos. 6,843,919, 6,653,519, 6,417,423, RE39,098, 6,087,294, 6,057,488, and 5,990,373, all of which are incorporated by reference in their entireties).

In case that the air stable nanoparticles are utilized, and they are distributed evenly through the tobacco product (particularly a cigar or cigarette), the heat generated would cause the coating to be removed/burned of exposing a fresh nanoparticle available for chemical interaction with the hazardous compounds. Exemplary air stable nanoparticles include those selected from the group consisting of MgO, SrO, BaO, CaO, TiO₂, ZrO₂, FeO, V₂O₃, V₂O₅, Mn₂O₃, Fe₂O₃, NiO, Fe₃O₄, CuO, Al₂O₃, SiO₂, ZnO₂, Ag₂O, the corresponding hydroxides of the foregoing, and mixtures thereof at least partially coated with a quantity of a coating material other than metal oxide coatings. As used herein, “coated” or “coating” is intended to refer to coatings which only physically coat the particles, as well as those coatings which modify or react with the metal oxide surfaces. Preferred coating materials include those selected from the group consisting of surfactants, oils, polymers (both synthetic and natural; e.g., silicone rubber and cellulose and its derivatives), resins, waxes, silyls, and mixtures thereof.

The construction of a tobacco product according to the present invention begins with the selection of a solid nanocrystalline particle sorbent material capable of adsorbing and/or chemically reacting with at least one undesired compound produced by burning tobacco. The nanocrystalline particle material is dispersed within the tobacco product (such as in the tobacco itself, within a filter element, or as a coating on or embedded within fibers of the wrapping paper). FIG. 1 depicts a cigarette 10 comprising an outer paper wrapping 12 having a quantity of nanocrystalline particles 14 coated thereupon or dispersed with the fibers thereof. FIG. 2 shows a cigarette 16 comprising a quantity of tobacco 18 having nanocrystalline particles dispersed therein inside of an outer paper wrapping 20. Cigarette 16 also includes a conventional filter 22. FIG. 3 illustrates yet another cigarette 24 in accordance with the present invention that comprises a filter 26 having a quantity of nanocrystalline particles 28 incorporated therein. Cigarette 24 likewise comprises a quantity of tobacco 30 within an outer paper wrapping 32. It is also within the scope of the present invention to provide a cigarette that incorporates two or all three features shown in the above drawings.

For example, the cigarette may be constructed with the nanocrystalline particle-containing paper 12, filter 26, and tobacco 18.

The nanocrystalline particles may also be provided as granular sorbents, sorbents attached to a support, or as a bed of particles such as a packed column within the tobacco product. The tobacco may be in the form of relatively intact leaves (such as in a cigar) or comminuted and/or shredded into fine particulates (such as in cigarettes). In certain embodiments, the tobacco product comprises between about 0.001% to about 2% by weight of the nanocrystalline particles.

In certain embodiments of the present invention, the nanocrystalline particles resist reacting with moisture, and other components found in the environment (i.e., carbon dioxide) for a duration of up to 18 months (the shelf life of the cigarette). In other embodiments, the nanocrystalline material is capable of selectively neutralizing toxic compounds while allowing nicotine to freely pass on to the user, and without significantly altering the burn characteristics of the tobacco or altering the tobacco flavors.

The temperature range of contacting the nanoparticle sorbent with the undesired compound inside the cigarette filter ranges from ambient to 800° C. The time of contact ranges from brief (fraction of a second) to the life of smoked product, or from less than a minute to about 20 minutes.

In addition to adsorption/removal of harmful components, the present nanocrystalline particles are also capable of destruction of certain contaminants. The sequence below illustrates the destruction of aldehydes by carbonyl adsorption on surface cites of the metal oxide followed by the aldehydic hydrogen dissociation.

The reaction schemes below illustrate the destruction of ethylene oxide via basic and acidic catalytic pathways.

Base Catalytic Pathway

Acid Catalytic Pathway

Technical data on the efficacy of hazardous material sorption is provided in U.S. Pat. No. 7,276,640 and PCT Application Publication WO 2007/051145, both of which are hereby incorporated by reference in their entireties.

EXAMPLES

The following examples set for experimental data regarding the efficacy of certain nanocrystalline particles in the removal of certain chemical components of tobacco smoke. These examples are provided by way of illustration and nothing therein should be viewed as limiting the scope of the present invention.

Example 1

In this example, data pertaining to the time for NOx and HCN to break through a packed column of the indicated sorbent at the stated moisture level is given below. Tested adsorbents were granulated with granule size 12-30 mesh. Flow of the gas for NO₂ was 5.3 slpm through a bed 3 cm in diameter and having a bed depth of 3.7 cm. Flow of the gas for HCN was 2.0 slpm through a bed 3 cm in diameter and having a bed depth of 1.0 cm.

Nitrogen Dioxide (NO₂) 200 ppm Breakthrough Time (min) Sorbent 25% RH 80% RH Zeolite 13X 102 66 NanoActive ® CaO Plus¹ 238 79 ¹Available from NanoScale Corporation, Manhattan, Kansas (≦20 nm crystallite size, ≧90 m²/g)

Hydrogen Cyanide (HCN) 50 ppm Sorbent Breakthrough Time NanoActive ® ZnO² Greater than 6 hours ²Available from NanoScale Corporation, Manhattan, Kansas (≦10 nm crystallite size, ≧70 m²/g)

Example 2

Breakthrough tests were conducted using 870 mg/m³ (330 ppm) of sulfur dioxide mixed with air. The tests were carried out at room temperature (19-23° C.). A superficial gas velocity was 12 ft/min (6 cm/s) and the bed thickness was 10 mm. Tested adsorbents were granulated with granule size 12-30 mesh (activated carbons) or 16-35 mesh (nanoparticle formulations).

The table below compares SO₂ breakthrough times for NanoActive® MgO (characterized in Example 3 below) and two popular activated carbon sorbents. The data strongly favors NanoActivce® MgO in that it outperformed both activated carbons both before and after humidity exposure.

Breakthrough Time (hr) (measured at 10% of initial SO₂ concentration) concentration Dry 50% Relative Adsorbent (mg/m³) Conditions Humidity BPL carbon 870 0.1 1.5 ASZM-TEDA carbon 870 0.8 1.5 NanoActive ® MgO 870 4 2

Example 3

Breakthrough tests with hydrogen chloride were conducted with an air stream containing 3100 mg/m³ (2100 ppm) of agent at room temperature (20-25° C.). A superficial gas velocity was 12 ft/min (6 cm/s) and the bed thickness was 10 mm. Tested adsorbents were granulated, with granule size 12-30 mesh (activated carbons) or 16-35 mesh (nanoparticle formulations). Tests for this agent were carried out at 35% relative humidity instead of 50% relative humidity used for other agents. This change was needed to avoid condensation and corrosion caused by the HCl agent in the breakthrough apparatus. FIG. 4 presents the hydrogen chloride air filtration removal capacities (mg/g) for the BPL and ASZM-TEDA carbons and the following NanoActive® metal oxides: MgO, MgO Plus, TiO₂, Al₂O₃, Al₂O₃ Plus, and ZnO, characterized as follows.

Surface Area, Sorbent BET (m²/g) Crystallite size (nm) NanoActive ® MgO ≧230 ≦8 NanoActive ® MgO Plus ≧600 ≦4 NanoActive ® TiO₂ ≧500 Amorphous NanoActive ® Al₂O₃ ≧275 Amorphous NanoActive ® Al₂O₃ Plus ≧550 Amorphous NanoActive ® ZnO ≧70 ≦10 

Air filtration performance of activated carbons towards HCl was outperformed under both dry and humidified conditions. Under dry conditions, NanoActive®, ZnO outperformed both carbons by at least 180% (two-sample T-type hypothesis test and a 95% confidence level). Under humidified conditions, NanoActive® Al₂O₃ Plus outperformed activated carbons by at least 332% (two-sample T-type hypothesis test and a 95% confidence level) and reached an exceptional removal capacity of (1340+/−270) mg/g.

The breakthrough tests conducted with hydrogen chloride show clear advantages of using selected NanoActive® metal oxide formulations under dry and humidified conditions In particular, NanoActive® Al₂O₃ Plus had greater than four times the removal capacity of the ASZM-TEDA carbon under humidified conditions.

Example 4

Breakthrough tests with acetaldehyde were conducted with an air stream containing 540 mg/m³ (300 ppm) of CH₃CHO in air at room temperature (20-25° C.). A superficial gas velocity was 12 ft/min (6 cm/s), and the bed thickness was 10 mm. Tested adsorbents were granulated, with granule size 12-30 mesh (activated carbons) or 16-35 mesh (nanoparticle formulations). FIG. 5 presents the acetaldehyde air filtration removal capacities for the BPL and ASZM-TEDA carbons and the following NanoActive® metal oxides: MgO, MgO Plus, TiO₂, Al₂O₃, and Al₂O₃ Plus (previously characterized herein).

Under dry conditions, all tested metal oxide formulations outperformed both activated carbons. NanoActive® MgO Plus, TiO₂, and Al₂O₃ outperformed both carbons by at least 208%, as evaluated using the two-sample T-type hypothesis test and a 95% confidence level. Under humidified conditions, NanoActive® MgO outperformed activated carbons by at least 46% (two-sample T-type hypothesis test and a 95% confidence level).

The breakthrough tests conducted with the acetaldehyde show a clear advantage of using selected NanoActive® metal oxide formulations under dry and humidified conditions. This is particularly significant since the removal capacities for this agent for both activated carbons are relatively low, in the 8-23 mg/g range. Such low capacities make it difficult to use these sorbents in air filtration systems. Typically larger capacities, at least 200-300 mg/g and preferably higher, are needed.

Example 5

In this example, a number of sorbent materials were tested for efficacy in removing toluene vapor from air under stationary, dynamic, and static test conditions. Further testing was performed on selected sorbents for removal of toluene, acetaldehyde, dietheyl amine, and ethyl mercaptan.

Materials

Concentrated hydrochloric acid, 28-30% aqueous ammonia, hexadecyl-trimethylammonium bromide (C16TMABr), tetraethyl orthosilicate (TEOS), LE-4 polyoxyethylene lauryl ether, aluminum sulfate (Al₂(SO₄)₃.18H₂O), triethoxyoctyl silane (TES), and phenyl triethoxyoctyl silane (PTES) were purchased from Sigma-Aldrich, Sodium hydroxide, ethanol (histological) and toluene (A.C.S. grade) were obtained from Fisher. Tetrabutyl ammonium hydroxide (TBAOH) was obtained from Alfa Aesar. Ludox As-40 (40% wt) silica was obtained from Grace Davison. Zeolite nanocrystalline CBV 400 and CBV 8014 were obtained from Zeolyst International. Nanocrystalline titanium dioxide (NanoActive® TiO₂ from NanoScale Corporation) and trimetallic oxide (MgO:TiO₂:Al₂O₃ 1:2:1) was synthesized. All chemicals were used as obtained without further purification.

Sample Synthesis

PTES hybrid mesoporous silica was synthesized according to the method reported by Burkett and coworkers. Burkett, S. L., Sims, S. D., Mann, S. Synthesis of Hybrid Inorganic-Organic Mesoporous Silica by Co-condensation of Siloxane and Organosiloxane Precursors, Chem. Commun., 1996, 1367-1368.

A LE-4 polymer assisted silicate was synthesized following the method reported by Lee and coworkers. Lee. J. W. Lee, J. W., Shim, W. G. S., Suh, S. IL., Moon, II. Adsorption of Chlorinated Volatile Organic Compounds on MCM-48, J. Chem. Eng. Data, 2003, 48, 381-387.

An Al-ZSM-5 silicate was synthesized following the method reported by Grieken and coworkers (van Grieken, R., Sotelo, J. L., Menendez, J. M., Melero, J. A. Anomalous Crystallization Mechanism in the Synthesis of Nanocrystalline ZSM-5, Microporous Mesoporous Water., 2000, 39, 135-147), except that the preparation was scaled up to twice its original scale, and TPAOH, in original literature, was substituted by TBAOH in the same molar ratio, as the former reagent was no longer carried by the original vender.

Samples Characterization

The BET (Brunauer-Emmet-Teller method) surface area and XRD (powder X-ray diffraction) measurements were taken for all seven samples. BET analysis was performed on a Quantachrome Nova 2200 BET instrument. Each sample was first out gassed and then cooled to 77 K, followed by exposure to nitrogen. The amount of nitrogen adsorbed as a single layer was measured. The surface area was directly calculated from the number of molecules absorbed and the area occupied by each. XRD were performed on a Shimadzu XRD-6000 instrument. The results are summarized below.

Sample Sample Name SSA, m²/g XRD, 2θ 1 CBV400 zeolite 590.6 Crystalline: 12, 16, 19, 24, 27, 30, 31, 32, 34 2 CBV8014 zeolite 371.9 Crystalline: 23, 24, 24.5 3 PTES hybrid 786.2 Amorphous mesoporous silica 4 LE-4 assisted silicate 1019 Amorphous 5 Al-ZSM-5 silicate 662.0 Amorphous 6 NanoActive ® TiO₂ 471.5 Amorphous 7 NanoScale trimetallic 533.0 Amorphous oxide MgO/TiO₂/Al₂O₃

Methods

a) Stationary Test Method with GC-FID Detection.

The test setup comprised a 245 ml gas tight glass reactor equipped with a sample holder inside for placement of the solids. All tests were performed in undesiccated ambient air. Initial experimentation showed that toluene liquid completely evaporates in the reactor within 1 h after injection, and an accurate calibration is possible within this time frame. For each test, 20 ul of liquid toluene was injected into the sealed reactor through the septum on the side arm and after 1 h a gas sample (1 ml) was taken from the reactor for analysis by GC-FID. The initial GC peak area was noted as A0. The reactor was then cleaned by air purging, the desired sorbent sample (0.6 g powder or 35-60 mesh granules) was loaded on the sample holder and the reactor sealed. Liquid toluene (20 ul, sorbent:toluene 10:1 w/w) was injected into the reactor without directly contacting the sorbent. A gas sample (1 ml) was analyzed by GC-FID after 1 h. The GC peak area was noted as A1. Percentage toluene removal by the sorbent was calculated using the formula 1−(A1/A0). The instrument used was a GC-FID 5890 series II, equipped with a 30 m×0.32 mm ID×0.25 um EC-Wax column. The temperature of the injector and the detector was 265° C., the heating program was 60-100° C. (stead at 60° C. for 10 min, followed by heating rate 5° C./min to 100° C. for 1 min; toluene retention time 4.7 min). Two replicates were carried out for each test.

b) Dynamic Test Method with FT-IR Detection.

The dynamic test condition was designed to mimic an air filtration test system that is used in solids testing. The FT-IR instrument (Thermo Electron Corporation) was equipped with a 2.5 L gas cell. A gas circulation pump was connected to the JR gas cell by steel tubing, forming sealable circulation pathway. A glass solid sample cell with filter frit was connected into the circulation pathway. All tests were performed in dry ambient air. After cleaning the test system by air purging, toluene (20 ul) was injected into the sealed IR cell, vaporized by brief spot heating, and circulated by the pump with simultaneous IR measurements. When IR spectra intensity stopped fluctuating, integration of the band region 3160-2834 cm-1 (C—H stretch) was noted as I0. The pump was then turned off and the desired sorbent (0.16 g, 35-60 mesh granules) was quickly loaded into the sample cell. The system was resealed and the pump was turned back on, continuously circulating toluene contaminated air through the sorbent sample. IR spectra of toluene in the vapor phase were taken at various time intervals by an automatic Macro program continuously for 3 hours. Spectra integration of the band region 3160-2834 cm⁻¹ at time t was noted as It. Percentage toluene vapor removal at a certain time t can be calculated using the formula 1−(It/I0). Two replicates were carried out for each test.

c) Static Test Method with GC-FID Detection.

The key differences between the previously described stationary test (a) and the static test herein are the quantities of air and concentrations of toluene the sorbents were exposed to. In these tests, the sorbents were challenged by exposure to a larger quantity of air combining very low concentrations of VOCs. Static tests were performed in a 4 L gas tight plastic container equipped with septum valves. All tests were performed in undesiccated ambient air. In each test, the container was cleaned out by air purging, injected with the desired VOC vapor so a definite VOC concentration in the container was reached (45 ppm for toluene, 50 ppm for acetaldehyde, and 100 ppm for both diethyl amine and ethyl mercaptan) and then allowed to sit for 30 min for vapor equilibration. (Time dependent control experiments indicated that 30 min is sufficient for equilibration of all VOCs tested.) Then a gas sample (2.5 ml) was taken from the container and analyzed by GC-FID. The GC peak area was noted as P0. The container was then cleaned out by air purging, a watch glass loaded with sorbent powder (0.67 g) was put into the container which was thereafter scaled and injected with the same amount of VOC) vapor, as mentioned above. Gas samples and GC-FID measurements were taken after 0.5, 1, 2, 18 and 24 hours. Right before the 0.5 h measurement, and right after the 18 h and 24 h measurement, the test chemical (1 ul) was analyzed by GC-FID in a validation and verification step. The corrected GC peak area obtained at t hour(s) was noted as Pt. Percentage VOC removal at t hour(s) was calculated using the formula 1−(Pt/P0). For toluene, the same GC-FID instrument and analyzing program as described in the stationary test method were used. For acetaldehyde, diethyl amine and ethyl mercaptan, injector and detector temperature was 215° C., heating program was 70-775° C. (steady at 70° C. for 5 min followed by heating rate 30° C./min to 175° C., finally steady at 175° C. for 1.5 min. retention time is 4.4 min for acetaldehyde, 2.6 min for ethyl mercaptan and 3.9 min for diethyl amine). Two replicates were carried out for each test.

Results and Discussion

The surface areas of the seven samples can be divided into four major groups: 300-500 m²/g (Samples 2 and 6), 500-700 m²/g (Samples 1, 5, and 7), 700-800 m²/g (Sample 3) and >1000 m²/g (Sample 4). Sample 2 has the lowest surface area while Sample 4 has the highest.

a) Stationary Test.

Stationary test results with sorbent:toluene (w/w) 10:1 are summarized below.

Sample 1 2 3 4 5 6 7 1 h Removal, % 96.8 ± 0.2 57.6 ± 0.9 75.5 ± 0.5 73.4 ± 3.4 72.0 ± 0 86.7 ± 0 76.4 ± 0.8

As seen from the above results, Sample 1 performed the best, in second place was Sample 6, the third place was shared by Samples 3, 4, 5 and 7, with Sample 2 as the least effective. The sorbents' performance ranking does not correlate directly with their surface area ranking except for Sample 2. This suggests that surface area is not the only factor that determines a sorbent's performance. After the stationary tests, Samples 1, 6, and 7 were recovered from the reactor and presence of toluene on them was confirmed by DRIFTS-IR (data not shown).

b) FT-IR Dynamic Test

FT-IR dynamic test results with sorbent:toluene (w/w) 10:1 is summarized below.

Sample 1 2 3 4 5 6 7 3 h Removal, % 99.4 ± 0.1 76.4 ± 0.2 49.8 ± 0.8 65.8 ± 0.5 67.4 ± 1.0 77.7 ± 0.2 82.2 ± 0.1

In this test, Sample 1 still performed the best, with second place shared by Samples 2, 6 and 7, and third place shared by Samples 4 and 5, and Sample 3 as the least effective Based on the performance ranking and the absolute quantities of adsorption, Samples 2 and 3 showed appreciable difference in stationary and dynamic tests).

Sample 1 2 3 4 5 6 7 Ranking in Stationary 1 4 3 3 3 2 3 Test Ranking in 1 2 4 3 3 2 2 Dynamic Test

To ascertain the effect of test conditions on apparent sorbent performance ranking, stationary tests were performed on Samples 2 and 3 as granules (35-60 mesh). The results were similar to that obtained with powder. This suggests that the physical form of sorbents (powder or granules) does not have much effect on the test outcome. The observed differences in performance ranking are likely due to differences in test environment (ambient humid air was used for stationary test while dry air for dynamic test).

1 h Toluene Removal 1 h Toluene Removal Material by Powder, % by Granules, % Sample 2 57.6 ± 0.9 62.0 ± 1.0 Sample 3 75.5 ± 0.5 80.4 ± 2.8

To study the relationship between toluene concentration and sorbent performance, dynamic tests were performed with different amounts of Sample 6 and toluene. The results are summarized below.

TiO₂ (mg)/Toluene (ul) 160/20 60/20 60/10 120/10 3 h Removal, % 77.7 ± 0.2 38.8 ± 0.2 47.8 ± 0.7 65.1 ± 0.4 Sorbent/Adsorbed 10:0.77 10:1.03 10:0.64 10:0.43 Toluene (w/w) Approximate 10 20 60 60 Equilibration Time, min

From the above dynamic test results, it is seen that with higher initial toluene concentration, the adsorption equilibration was attained faster. Also, the lower the TiO₂/toluene ratio, the larger the quantity of toluene adsorbed on TiO₂.

c) Static Test

The two samples that showed the best performance in the dynamic test Samples 1 and 7 (CBV 400 and trimetallic oxide), were selected for low concentration static tests with multiple VOCs. The results are summarized below.

VOC % VOC Removal, h (Conc., ppm) 0.5 1 2 18 24 Toluene 65.9 ± 3.1 100 ± 0  100 ± 0  100 ± 0  100 ± 0  (45) Acetal- 35.8 ± 6.7   78 ± 1.9 77.3 ± 0.5   75 ± 5.6 80.6 ± 0.2 dehyde (50) Diethyl 57.5 ± 0.1 75.5 ± 0.5 79.6 ± 0.5 67.9 ± 0.5 67.6 ± 0.1 Amine (100) Ethyl 65.8 ± 0.4 87.0 ± 0.2 91.4 ± 0.1 77.4 ± 0.6 80.6 ± 3.0 Mercaptan (100) Toluene 82.6 ± 0.2 83.8 ± 2.8 83.5 ± 3.1 75.7 ± 0.8 71.2 ± 1.2 (45) Acetal- 87.2 ± 3.8 96.4 ± 1.0 98.3 ± 0.1 98.4 ± 0.6 100 ± 0  dehyde (50) Diethyl 60.6 ± 1.6 74.8 ± 1.4 85.8 ± 0.6 88.6 ± 2.0 87.8 ± 0.1 Amine (100) Ethyl 75.6 ± 0.6 86.9 ± 4.3 96.8 ± 1.7 80.8 ± 2.4 74.9 ± 3.4 Mercaptan (100)

As shown by this set of results, Sample 1 was better at toluene removal, adsorbing 100% toluene within the first hour, while Sample 7 was superior for adsorbing acetaldehyde and diethyl amine. The two samples adsorption capabilities for ethyl mercaptan were similar.

In 24 hours, diethyl amine and ethyl mercaptan partially desorbed from Sample 1, while toluene and ethyl mercaptan partially desorbed from Sample 7.

Among all sorbents tested, CBV 400 (zeolite) was the best for toluene removal from air, regardless of the test conditions used, while trimetallic oxide is a better universal VOCs sorbent than CBV 400. It was also found that higher surface area does not necessarily lead to better performance of a sorbent in VOC removal. 

1. A tobacco product comprising nanocrystalline particles and tobacco.
 2. The tobacco product of claim 1, wherein said tobacco product is a cigarette or cigar.
 3. The tobacco product of claim 1, wherein said tobacco and said nanoparticles are contained within a paper wrapping.
 4. The tobacco product of claim 3, wherein said nanocrystalline particles are dispersed within said tobacco.
 5. The tobacco product of claim 3, wherein said nanocrystalline particles are loaded upon or contained within the fibers of said paper wrapping.
 6. The tobacco product of claim 1, wherein said tobacco product comprises a fibrous filter portion.
 7. The tobacco product of claim 6, wherein said nanocrystalline particles are included within said filter portion and are configured to contact and adsorb smoke and/or toxic materials produced from the burning of said tobacco.
 8. The tobacco product of claim 1, wherein said nanocrystalline particles are selected from the group consisting of the oxides, hydroxides, halides, carbonates, and phosphates of metals, metalloids, and combinations thereof.
 9. The tobacco product of claim 8, wherein said nanocrystalline particles are selected from the group consisting of the oxides, hydroxides, halides, carbonates, nitrates, sulfates, and phosphates of transition metals, alkali metals, alkaline earth metal, lanthanide metals, and combinations thereof.
 10. The tobacco product of claim 1, wherein said nanocrystalline particles have an average surface area of at least 20 m²/g.
 11. The tobacco product of claim 1, wherein said nanocrystalline particles have an average crystallite size of between about 2 to about 25 nm.
 12. The tobacco product of claim 1, wherein said nanocrystalline particles are amorphous and have an average crystallite size of less than 2 nm.
 13. The tobacco product of claim 1, wherein said tobacco product comprises between about 0.001% to about 2% by weight of said nanocrystalline particles based upon the weight of the entire tobacco product.
 14. A method of reducing the level of reducing the level of undesirable components in tobacco smoke from a tobacco product comprising the step of incorporating a quantity of nanocrystalline particles into said tobacco product.
 15. The method of claim 14, wherein said nanocrystalline particles are combined with said tobacco prior to creation of said tobacco product.
 16. The method of claim 14, wherein said tobacco product is a cigarette or cigar.
 17. The method of claim 14, wherein at least a portion of said nanocrystalline particles are incorporated into a filter portion of said tobacco product.
 18. The method of claim 14, wherein said nanocrystalline particles are loaded upon or contained within the fibers of a paper wrapping of said tobacco product.
 19. The method of claim 14, wherein said nanocrystalline particles are selected from the group consisting of the oxides, hydroxides, halides, carbonates, and phosphates of metals, metalloids, and combinations thereof.
 20. The method of claim 19, wherein said nanocrystalline particles are selected from the group consisting of the oxides, hydroxides, halides, carbonates, and phosphates of transition metals, alkali metals, alkaline earth metal, lanthanide metals, and combinations thereof.
 21. The method of claim 14, wherein said nanocrystalline particles have an average surface area of at least 20 m²/g.
 22. The method of claim 14, wherein said nanocrystalline particles have an average crystallite size of between about 2 to about 25 nm.
 23. The method of claim 14, wherein said nanocrystalline particles are amorphous and have an average crystallite size of less than 2 nm.
 24. The method of claim 14, wherein said tobacco product comprises between about 0.001% to about 2% by weight of said nanocrystalline particles based upon the weight of the entire tobacco product.
 25. The method of claim 14, including the step of combusting a portion of said tobacco product containing said tobacco thereby generating tobacco smoke and one or more undesirable compounds.
 26. The method of claim 25, said nanocrystalline particles sorbing at least one of said one or more undesirable compounds contained in said tobacco smoke.
 27. The method of claim 26, said one or more undesirable compounds being selected from the group consisting of carbon monoxide, hydrogen cyanide, nitrogen oxides, formaldehyde, acrolein, benzene, N-nitrosamines, nicotine, phenol, and polyaromatic hydrocarbons (PAHs). 